The collection of blood samples from a patient are integral in the diagnosis of disease, and the monitoring of therapy. One method of collecting blood is commonly referred to as the "fingerstick". This method involves cutting the skin with a lancing device and collecting the blood from the resulting wound.
The earliest collecting devices were glass tubes, sometimes manufactured with special shapes such as tapered ends. About 10 years ago, manufacturers began introducing specially designed plastic collectors in which the collected blood sample could be directly centrifuged to yield serum or plasma. However, these devices have a number of deficiencies.
One problem associated with these prior blood collectors is that most of them rely on gravity which requires that the drop of blood accumulating at the wound must become large enough to flow down a spout or a funnel which is plastic. Plastic is hydrophobic and therefore, non-wetable, which makes the flow of blood down a plastic spout or funnel very difficult. Furthermore, due to the difficult passage of the blood over a plastic surface, the blood may have time to clot before reaching the anticoagulant usually located in or near the bottom of the blood collector. The clotting may be serious enough to block the flow of blood, or micro-clots may form which interfere with the subsequent analysis of the blood especially the counting of cells in a blood cell counter. Therefore, the prior blood collectors are very technique dependent to prevent the clotting of blood during the blood collection process.
Another problem associated with prior blood collecting devices is that they are generally unsuitable for use with new, smaller, automated blood analyzers developed in recent years. For example, the pipettor associated with one of these newer instruments cannot reach the prepared plasma or serum in most of the prior art collectors because the blood collector is too long and/or too narrow.
Another type called the KABE Collector has several deficiencies which are identified in the detailed description relating to prior art, infra.